@bancor/carbon-sdk

Carbon SDK

Disclaimer

This SDK is in beta. We cannot be held responsible for any losses caused by use of the SDK.

Overview

The SDK is a READ-ONLY tool, intended to facilitate working with Carbon contracts. It's a convenient wrapper around the Carbon matching algorithm and Carbon contracts, allowing programs and users get a ready to use transaction data that will allow them to manage strategies and fulfill trades

Installation

Use npm or yarn to install carbon-sdk.

yarn add @bancor/carbon-sdk

Usage

import {
  PayableOverrides,
  TradeActionBNStr,
  TokenPair,
  MatchActionBNStr,
  StrategyUpdate,
  EncodedStrategyBNStr,
} from '@bancor/carbon-sdk';
import { Toolkit } from '@bancor/carbon-sdk/strategy-management';
import { ChainCache, initSyncedCache } from '@bancor/carbon-sdk/chain-cache';
import {
  ContractsApi,
  ContractsConfig,
} from '@bancor/carbon-sdk/contracts-api';

let api: ContractsApi;
let sdkCache: ChainCache;
let carbonSDK: Toolkit;
let isInitialized = false;
let isInitializing = false;
const MAX_BLOCK_AGE = 2000; // past this many blocks, the SDK won't attempt to catch up by processing events and instead call the contracts for strategy info.

const init = async (
  rpcUrl: string,
  config: ContractsConfig,
  decimalsMap?: Map<string, number>,
  cachedData?: string
) => {
  if (isInitialized || isInitializing) return;
  isInitializing = true;
  const provider = new StaticJsonRpcProvider(
    { url: rpcUrl, skipFetchSetup: true },
    1
  );
  api = new ContractsApi(provider, config);
  const { cache, startDataSync } = initSyncedCache(api.reader, cachedData, MAX_BLOCK_AGE);
  sdkCache = cache;
  carbonSDK = new Toolkit(
    api,
    sdkCache,
    decimalsMap
      ? (address) => decimalsMap.get(address.toLowerCase())
      : undefined
  );
  sdkCache.on('onPairDataChanged', (affectedPairs) =>
    onPairDataChanged(affectedPairs)
  );
  sdkCache.on('onPairAddedToCache', (affectedPairs) =>
    onPairAddedToCache(affectedPairs)
  );
  await startDataSync();
  isInitialized = true;
  isInitializing = false;
};

Notes

1. The SDK Logger supports 3 verbosity levels:

• 0 (default) only prints errors and important logs.
• 1 (debug) prints highly verbose logs.
• 2 (debug readable) is same as 1 but also converts any BigNumber to an easy to read string (impacting performance).

To use it in Node, set the environment variable CARBON_DEFI_SDK_VERBOSITY to the desired level. To use it from a browser app do, before importing the SDK:

window.CARBON_DEFI_SDK_VERBOSITY = 2;

2. For usage with contracts version < 5, without the enhanced range for trade by source:

window.LEGACY_TRADE_BY_SOURCE_RANGE = true;

Authors

• @zavelevsky

Contributing

Pull requests are welcome!

For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT